<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
      /*id选择器*/
    #p1{color: red}
      /*类选择器*/
      .c1{color: green}
      /*分组选择器*/
      a,#p1,.c1{
          background-color: yellow;
      }
      input[type='text']{color: red}
      input[type='password']{background-color: green}
      /*任意元素选择器*/
      *{
          /*边框:  粗细 边框  颜色*/
          border: 1px solid red;
      }
  </style>
</head>
<body>
<input type="text">
<input type="password">
<a href="">超链接</a>
<p id="p1">苹果</p>
<p>香蕉</p>
<p class="c1">橘子</p>
<div>电视</div>
<div>冰箱</div>
<div class="c1">洗衣机</div>

</body>
</html>